from typing import Optional
def hold_last(value: Optional[float], last: Optional[float]) -> Optional[float]:
return last if value is None else value
class MovingAverageFilter:
def __init__(self, window: int = 5):
assert window >= 1
self.window = window
self.buf = []
self.sum = 0.0
def update(self, x: float) -> float:
''' Update the moving average filter with a new value x.
Returns the current filtered value.
'''
self.buf.append(x)
self.sum += x
if len(self.buf) > self.window:
self.sum -= self.buf.pop(0)
return self.sum / len(self.buf)
